Z4 M Definitive Wheel Spec Thread

[JJZ4MR]

Love the stockers, what type of Graphite Metallic w/ Matte Clear ? As in what was done, by who and it you don't mind sharing what type of price did you pay ? I'm looking to do the same and have done some research in resurfacing them. My stock wheels I love, but the paint/clearcoat is peeling in a couple spots and it's an eyesore that has to go. I wrapped them in a new set of Bridgestone Potenza RE-71 R's F- 235/40, R-265/35. Been doing some AutoX and the grip is amazing !

[zwest1]

I see lots of indications that people have wider tires in the front (i.e. 45) than the rear (i.e. 40).

Why less profile in the rear?

[Jackal]

Originally Posted by zwest1

I see lots of indications that people have wider tires in the front (i.e. 45) than the rear (i.e. 40).

Why less profile in the rear?

This isn't a "wider" tire thing. This is an overall diameter thing. The following does not apply to square setups.

The second number is an aspect ratio; meaning that the height of the tire (rim to outer edge) is equal to X% (45% or 40% in your quote) of the tire's width.

To maintain similar overall diameters of tires (Top to bottom), as you go wider on the rear tire, you must eventually step down in aspect.

I have attached a tire rack comparison in case I am not explaining it right. As you go from a 245/40 to a 265/40 and 265/35, look at what happens to the overall diameter.
http://www.1010tires.com/Tools/Tire-...0R18/265-35R18

[zwest1]

"Wider" was a bad word choice on my part, but you got the crux of my question. And I totally follow - embarrassed that I couldn't figure that out on my own.

[m5m3mc]

I just got an email from a friend. He has an '07 Z4MC (stock suspension, no track use) and wants to run a 285/30x19 Conti Extremecontact Sport with a tread width of 10.2" on a 19x10 ET TBD but hasn't ordered it yet so there's room for adjustment. He says his goal is a no-rub fitment but hopefully w/o the tire sticking out of the wheel arch very much. He thinks from a 3/4 front view the rear body/quarter looks too narrow and that too much tire outside the quarter will look stupid and I agree totally with that viewpoint. I told him around an ET28 but figured I better run that by here with those who are/have run 285's. Thoughts?

[scrammer]

Originally Posted by JJZ4MR

Love the stockers, what type of Graphite Metallic w/ Matte Clear ? As in what was done, by who and it you don't mind sharing what type of price did you pay ? I'm looking to do the same and have done some research in resurfacing them. My stock wheels I love, but the paint/clearcoat is peeling in a couple spots and it's an eyesore that has to go!

Dupli-Color® Wheel Coating Is what I used. I followed the directions to a T with 5 light coats of the graphite and three of the clear. Dupli-Color has some good videos on their site as reference

I painted the barrels from the back first coat and then reapplied every 8 minutes using a deck of playing cards between the tire and rim .... see YouTube.

I am lucky enough to have a second set of rims so it made the job quite easy.

I used two cans of paint and one clear and all in was less than $50 cdn and it looks perfect

[JJZ4MR]

As soon as I get my " all four off the ground/lift problems figured out, I'm soooo doing this, as well as painting the calipers with G2 Red from Amazon ( $ 43 kit ) I've discussed with Z4M driver that did his and he is very happy. Pics on here somewhere.

[Over it]

So who's running a 285-30-18 out back? What's your set-up?

[mpathic]

Tried 285/30 Contis on the rear on 18x9.5ET22 wheels, too wide a cross section, not enough wheel well width, way too much sidewall flex in transitions. Did look cool and fill out the wheel well completely but scuffed inside and out on dips and bumps that compressed the suspension on both sides. 275's are the functional limit for best handling within the wheel well limitations.

[SDCoupe]

Finally got my wheels and tires mounted. Apex 18 inch Arc-8 anthracite 9.5 inch rear rim with 275/35 and 245/40 on 8.5 inch front. No rubbing. Stock suspension. This size preserves the original rolling diameter.

[Eson]

18x9.5" ET35, 18x10" ET25 - 255/275. -2° F, -1.8° R.

[coh661]

Originally Posted by Eson

18x9.5" ET35, 18x10" ET25 - 255/275. -2° F, -1.8° R.

No rub or fender rolling on the fronts?

[Eson]

Originally Posted by milamookie

No rub or fender rolling on the fronts?

No rub anywhere with all stock fenders.

[brother i]

Originally Posted by Eson

No rub anywhere with all stock fenders.

Good looking car!
The wheels look larger than 18", from that angle. Possibly because it's lowered?

[ried]

Looking at the Apex ARC-8 wheels.

Are people running 18x9 ET30 up front without issues? I'd like the more concave wheels up front, but the narrowest size is 18x9.

The 18x8.5 ET38 wheels are known to fit - but they're flatter, less concave.

245/40/R18 tires in both cases.

[AmmarYasirA]

Originally Posted by ried

Looking at the Apex ARC-8 wheels.

Are people running 18x9 ET30 up front without issues? I'd like the more concave wheels up front, but the narrowest size is 18x9.

The 18x8.5 ET38 wheels are known to fit - but they're flatter, less concave.

245/40/R18 tires in both cases.

Im running Apex ARC-8's with these specs:

18/9.5/et35 with Michellin PSS 255/35

18/10/et25 with Michellin PSS 275/35

Completely stock suspension. Mine doesn't rub at all.

[ried]

Originally Posted by AmmarYasirA

Im running Apex ARC-8's with these specs:

18/9.5/et35 with Michellin PSS 255/30

18/10/et25 with Michellin PSS 275/30

Completely stock suspension. Mine doesn't rub at all.

I wonder if having such low profile tires is enabling the clearance? 245/40/18 is going to be significantly taller, and has a 7% difference in rotational speed.

Would love to hear from someone with the 18x9" ARC-8 wheel with a 245/40/R18 tire.

[AmmarYasirA]

Originally Posted by ried

I wonder if having such low profile tires is enabling the clearance? 245/40/18 is going to be significantly taller, and has a 7% difference in rotational speed.

Would love to hear from someone with the 18x9" ARC-8 wheel with a 245/40/R18 tire.

Ahhh yes. Completely glossed over that bit. But yeah, probably. On the other hand, they do make a concave face with better offsets/widths to accommodate what you're trying to go for. Although 40 is pretty high, you miiiggghhttt be able to get away with it.

[Eson]

Originally Posted by AmmarYasirA

Im running Apex ARC-8's with these specs:

18/9.5/et35 with Michellin PSS 255/30

18/10/et25 with Michellin PSS 275/30

Completely stock suspension. Mine doesn't rub at all.

Your sidewalls are too skinny. You can get away with these tire widths and 35-series sidewalls both F/R without rubbing, too. If you opt for the 245mm, a 245/40/18 would be the ticket.

[Eson]

Originally Posted by ried

I wonder if having such low profile tires is enabling the clearance? 245/40/18 is going to be significantly taller, and has a 7% difference in rotational speed.

Would love to hear from someone with the 18x9" ARC-8 wheel with a 245/40/R18 tire.

This will work with nearly stock camber settings (-1.5° or so; obtainable with stock tophats) as it's only 1mm less aggressive on the outside than my car. The sidewall will be a little bit more square on the 9" compared to the 9.5", but it'll look great and work well. Go 245/40/18 - not a smaller sidewall as mentioned above.

[ried]

Originally Posted by SDCoupe

Finally got my wheels and tires mounted. Apex 18 inch Arc-8 anthracite 9.5 inch rear rim with 275/35 and 245/40 on 8.5 inch front. No rubbing. Stock suspension. This size preserves the original rolling diameter.

I have this exact setup, using Michelin Pilot Sport 4S tires. At full lock (left or right), I get slight rubbing on the front fender liners. When turning right, the outside edge of the tire touches the driver side fender liner, and vice-versa. The tires are touching the little access panel cover.

These are brand new fender liners and seem properly installed. Is this normal? Didn't think 245/40/R18 on an 8.5 inch front ARC-8 wheel would be pushing the limit here. It only happens at or near full lock, but still...

[SDCoupe]

Originally Posted by ried

I have this exact setup, using Michelin Pilot Sport 4S tires. At full lock (left or right), I get slight rubbing on the front fender liners. When turning right, the outside edge of the tire touches the driver side fender liner, and vice-versa. The tires are touching the little access panel cover.

These are brand new fender liners and seem properly installed. Is this normal? Didn't think 245/40/R18 on an 8.5 inch front ARC-8 wheel would be pushing the limit here. It only happens at or near full lock, but still...

I don't think that is normal. I have Michelin super sports and there is plenty of room at full lock. Stock size 225/45 tires up front is 25.9 inches in diameter and 802 revolutions per minute. A 245/40 is actually smaller diameter at 25.7 inches and 809 revolutions per minute. Make sure your rims are the correct offset. Or it could be that the 4S tires are slightly wider than the super sports.